Heat the barbecue. If you are using coals, wait until they turn white. If you are indoors, heat a griddle pan. Cut four pieces of foil that will easily wrap a piece of salmon and lay them on the work surface. Spread a little butter onto the centre of each piece of foil to stop the salmon sticking. Lay the salmon on top. Mix the soy with the honey and divide it between the parcels, pouring it over the salmon. Dot any remaining butter on top and then fold the foil around the salmon tightly to make a parcel.
Put the parcels on the barbecue or griddle and cook for 5-10 mins. Check one parcel to see how it’s getting along but be careful – it will be hot. Once the salmon is cooked, open the parcels and scatter some sesame and spring onion into each.
Mix the cucumber with a few drops of sesame oil and season with a little salt. Serve the salmon with the cucumber salad.